Buggy code:
public class GFileUtils { public static final String FILE_SEPARATOR = System . getProperty ( "file.separator" ) ; public static FileInputStream openInputStream ( File file ) { } public static FileOutputStream openOutputStream ( File file ) { } public static String byteCountToDisplaySize ( long size ) { } public static void touch ( File file ) { } public static File [ ] convertFileCollectionToFileArray ( Collection files ) { } public static Collection listFiles ( File directory , IOFileFilter fileFilter , IOFileFilter dirFilter ) { } public static Iterator iterateFiles ( File directory , IOFileFilter fileFilter , IOFileFilter dirFilter ) { } public static Collection listFiles ( File directory , String [ ] extensions , boolean recursive ) { } public static Iterator iterateFiles ( File directory , String [ ] extensions , boolean recursive ) { } public static boolean contentEquals ( File file1 , File file2 ) { } public static File toFile ( String ... filePathParts ) { } public static File toFile ( URL url ) { } public static File [ ] toFiles ( URL [ ] urls ) { } public static List < String > toPaths ( Collection < File > files ) { } public static List < URL > toURLs ( Iterable < File > files ) { } public static URL [ ] toURLArray ( Collection < File > files ) { } public static URL [ ] toURLs ( File [ ] files ) { } public static void copyFileToDirectory ( File srcFile , File destDir ) { } public static void copyFileToDirectory ( File srcFile , File destDir , boolean preserveFileDate ) { } public static void copyFile ( File srcFile , File destFile ) { } public static void copyFile ( File srcFile , File destFile , boolean preserveFileDate ) { } public static void copyDirectoryToDirectory ( File srcDir , File destDir ) { } public static void copyDirectory ( File srcDir , File destDir ) { } public static void copyDirectory ( File srcDir , File destDir , boolean preserveFileDate ) { } public static void copyDirectory ( File srcDir , File destDir , FileFilter filter ) { } public static void copyDirectory ( File srcDir , File destDir , FileFilter filter , boolean preserveFileDate ) { } public static void copyURLToFile ( URL source , File destination ) { } public static void deleteDirectory ( File directory ) { } public static boolean deleteQuietly ( File file ) { } public static void cleanDirectory ( File directory ) { } public static boolean waitFor ( File file , int seconds ) { } public static String readFileToString ( File file , String encoding ) { } public static String readFileToString ( File file ) { } public static byte [ ] readFileToByteArray ( File file ) { } public static List readLines ( File file , String encoding ) { } public static List readLines ( File file ) { } public static class TailReadingException extends RuntimeException { public TailReadingException ( Throwable throwable ) { } } public static String tail ( File file , int maxLines ) throws GFileUtils . TailReadingException { } public static LineIterator lineIterator ( File file , String encoding ) { } public static LineIterator lineIterator ( File file ) { } public static void writeStringToFile ( File file , String data , String encoding ) { } public static void writeStringToFile ( File file , String data ) { } public static void writeByteArrayToFile ( File file , byte [ ] data ) { } public static void writeLines ( File file , String encoding , Collection lines ) { } public static void writeLines ( File file , Collection lines ) { } public static void writeLines ( File file , String encoding , Collection lines , String lineEnding ) { } public static void writeLines ( File file , Collection lines , String lineEnding ) { } public static void forceDelete ( File file ) { } public static void forceDeleteOnExit ( File file ) { } public static void forceMkdir ( File directory ) { } public static long sizeOfDirectory ( File directory ) { } public static boolean isFileNewer ( File file , File reference ) { } public static boolean isFileNewer ( File file , Date date ) { } public static boolean isFileNewer ( File file , long timeMillis ) { } public static boolean isFileOlder ( File file , File reference ) { } public static boolean isFileOlder ( File file , Date date ) { } public static boolean isFileOlder ( File file , long timeMillis ) { } public static long checksumCRC32 ( File file ) { } public static Checksum checksum ( File file , Checksum checksum ) { } public static void moveDirectory ( File srcDir , File destDir ) { } public static void moveDirectoryToDirectory ( File src , File destDir , boolean createDestDir ) { } public static void moveFile ( File srcFile , File destFile ) { } public static void moveFileToDirectory ( File srcFile , File destDir , boolean createDestDir ) { } public static void moveToDirectory ( File src , File destDir , boolean createDestDir ) { } public static File canonicalise ( File src ) { } public static List < File > getSubDirectories ( File directory ) { } public static void addSubDirectories ( final File directory , final Collection < File > subDirectories ) { } public static List < File > getSubFiles ( File directory ) { } public static boolean createDirectoriesWhenNotExistent ( File ... directories ) { } public static void createDirectory ( File directory ) { <START_BUG> if ( ! ( directory . mkdirs ( ) ) ) { <END_BUG> throw new UncheckedIOException ( ( "Failed<seq2seq4repair_space>to<seq2seq4repair_space>create<seq2seq4repair_space>directory<seq2seq4repair_space>" + directory ) ) ; } } }

Fix:
if ( ( ! ( directory . exists ( ) ) ) && ( ! ( directory . mkdirs ( ) ) ) ) {